The present invention relates to master controllers for operating robotic devices and, in particular, to such a controller for a robotic device having an arm like structure wherein the controller senses movement in the user's own arm and causes such movement to be mimicked in the robotic device and wherein the controller can be configured to be operated using either the right arm or the left arm.
Many robotic devices utilize robotic arms or arm like structures (herein generally referred to as arms) for conducting work at a site of use. Often such robotic arms are utilized in environments which are dangerous or hazardous to humans, such as deep sea construction or exploration, chemical or explosives handling, outer space construction and the like. Consequently, it is advantageous to have a master controller that links to the robotic device and that allows a user, especially a user in a remote area from the robotic device to control the robotic device. That is, the robotic device is slaved to the master controller, follows the movement of the user's arm, including the hand, and transfers this movement to the robotic device, so that the robotic arm can be controlled by the user to make movements in an intuitive manner similar or equivalent to the motions the user would make, if the user were performing the task by hand.
The art of such controllers has been well developed in sensors that sense motion in a part of a user's body and transmit the motion to the robotic device. It is also possible to provide such controllers with force feedback so that the user senses reactionary forces applied to the robotic arm, as by engagement with other structures and the like. Such devices are disclosed in U.S. Pat. No. 5,019,761 which is incorporated herein by reference.
Prior master controllers have been developed that provide for mimicking some movement of the upper and lower arm, such as U.S. Pat. Nos. 5,019,761 and D461,484; however, the present device is an improvement over the devices shown in those patents. In some prior art devices, the controller is too bulky, heavy, or cumbersome. A more significant problem has to do with positioning the controller to sense roll (rotation about the long axis of the forearm) and then allowing the user a wide range of movement, while providing a sturdy and easy to use control mechanism.
Incorporating roll sensing and mimicking has always presented difficulty to designers of such controllers. This is because it is desirable in such controllers for a handle, hand control, or hand grip to be allowed to rotate almost one hundred and eighty degrees without the hand grip or the user hitting another part of the controller. The prior art has had difficulty in providing such a controller. In the U.S. Pat. No. 5,019,761 this was accomplished by providing a circular track or hoop that followed a structure at the end of a remainder of the controller. Such a track is fragile and can easily become dirty or damaged by nicks or the like in the metal, thereby significantly reducing smoothness of operation over time and producing an undesirable resistance. Other devices have tried to resolve this by placing the point of rotation of the hand grip outside the axis of rotation of the forearm, but this does not properly mimic the arm. Still other attempts have been made to place the roll pivot and sensor to the front of the hand, but this makes the device bulky and cumbersome to use, especially in tight quarters.
In the past, such controllers were designed so that the arm was placed on the inside of the controller or to the left of a controller for a right handed person. Because the forearm also rotates the hand to the right, when the hand turns from palm up to palm down, such movement of the hand would be interfere with by any structure that extended directly from the rest of the controller to the hand grip.
Consequently, the arm was moved to the outside or right side of a right handed controller, and structure was developed that cooperates with such placement and that allows the hand grip to roll with the hand while maintaining the axis of rotation of the hand grip aligned with the axis of rotation of the forearm.
In the past, multiple link controllers which mimic the arm have been provided mostly in right handed configurations, since about 90 percent of the population is right handed. Left handed configurations of such controllers could also conceivably be provided. In most cases, it is not practical to provide both a right handed and a left handed controller for a given implement to be controlled.